Emergence of field pennycress (Thlaspi arvense L.): Comparison of two accessions and modelling

Abstract

a b s t r a c tMany weed species are becoming rare due to intense agricultural management, which leads to a decrease of biodiversity in agroecosystems. Cultivating some of these species for their oilseed content may help preserve them while profiting agronomically. Thlaspi arvense is one of these species with potential as an industrial crop. The aim of this work was to develop a model to describe the emergence of this species, and that can help to make decisions for its management, whether for conservation or production purposes. The emergence of two accessions of T. arvense, one from Spain and the other from USA, sown in Spain (Almenar) and USA (Morris), over two seasons (2011-12 and 2012-13) and in Riga (Latvia) over one season (2012), was followed to compare patterns and extent, as well as to develop emergence prediction models based on hydrothermal time (HTT) and photohydrothermal time (PhHTT). For the USA accession, the percentage of seeds that emerged was significantly higher than that of the Spanish accession. Both accessions presented two emergence peaks (autumn-winter and spring) in both localities, but while these peaks could be considered as two different flushes in Almenar -for both accessions -, they appeared to be a single flush disrupted by low winter temperatures in Morris. An HTT-based model was applicable for both accessions with less precision than the PhHTT-based one, which was more accurate in most cases but failed in certain circumstances for the USA accession. The differences in emergence percentage among accessions suggest that some accessions might be more amenable to being used as a crop. The two models developed in this work predicted the emergence of both accessions of T. arvense quite accurately. The inclusion of photoperiod in the hydrothermal time equation, creating a new unit that we have called photohydrothermal time, offers a possibility to obtain more accurate models.

Management of pennycress as a winter annual cash cover crop. A review

“…The majority of research related to pennycress planting date has occurred in the Upper Midwest, and there is evidence across growing locations in this region that early September sowing dates correspond to better establishment than late fall or early spring planting dates (Phippen et al 2010b;Gesch et al 2016;Dose et al 2017). However, in the Mediterranean climates, pennycress is not sown until early October, and, in some cases, may not be planted until early November (Royo-Esnal et al 2015Gesch et al 2016;Zanetti et al 2018). In the Upper Midwest, early fall sowing dates correspond to higher soil temperatures, which favors better germination and a longer vegetative growth period prior to winter frost (Phippen et al 2010b;Royo-Esnal et al 2017).…”

“…Pennycress is very susceptible to environmental influences, and water availability is the major limiting factor to germination and development (Royo-Esnal et al 2015;Gesch et al 2016). Germination occurs most readily in cool, wet conditions (Hazebroek and Metzger 1990a, b;Johnson et al 2015;Royo-Esnal et al 2015, and pennycress requires between 25 and 40 mm of water to germinate (Royo-Esnal et al 2015;Johnson et al 2017). Royo-Esnal et al (2015) noted that only 5% of seedlings emerged when soil moisture levels were low at planting compared with 18% emergence in years with adequate soil moisture.…”

“…Germination occurs most readily in cool, wet conditions (Hazebroek and Metzger 1990a, b;Johnson et al 2015;Royo-Esnal et al 2015, and pennycress requires between 25 and 40 mm of water to germinate (Royo-Esnal et al 2015;Johnson et al 2017). Royo-Esnal et al (2015) noted that only 5% of seedlings emerged when soil moisture levels were low at planting compared with 18% emergence in years with adequate soil moisture. What is unclear is the amount of moisture that is considered appropriate for pennycress production.…”

“…What is unclear is the amount of moisture that is considered appropriate for pennycress production. It is well established that pennycress is susceptible to moisture stress (Anderson and Best 1965;Hazebroek and Metzger 1990a;Royo-Esnal et al 2015); however, prior studies have merely used "adequate" to quantify the amount of moisture (Zanetti et al 2013;Royo-Esnal et al 2015). Determining the threshold of adequate versus inadequate moisture for pennycress development may warrant further research.…”

Short communication: Evaluation of a model for predicting Avena fatua and Descurainia sophia seed emergence in winter rapeseed

“…Weibull and Gompertz distributions have been used commonly in the development of weed emergence models (Izquierdo et al, 2013;Royo-Esnal et al, 2015). Model parameters of both species were estimated with SigmaPlot 12.0 using a non-linear regression fitting routine.…”